RAN Ying-ying, ZHAO Jun-wei, KONG Xiang-gui. Controlled Synthesis and Luminescence Properties of NaYF<sub>4</sub> ∶ Eu<sup>3+</sup> Nanoparticles/Hexagonal Prism[J]. 发光学报, 2010,31(4): 556-560
RAN Ying-ying, ZHAO Jun-wei, KONG Xiang-gui. Controlled Synthesis and Luminescence Properties of NaYF<sub>4</sub> ∶ Eu<sup>3+</sup> Nanoparticles/Hexagonal Prism[J]. 发光学报, 2010,31(4): 556-560DOI:
Controlled Synthesis and Luminescence Properties of NaYF4 ∶ Eu3+ Nanoparticles/Hexagonal Prism
nanoparticles/hexagonal prism are successfully prepared by hydrothermal method using trisodium citrate as chelator. The obtained samples were characterized by X-ray powder diffraction (XRD)
scanning electron microscopy (SEM)
Fourier transform infrared (FT-IR) spectra and luminescence spectra. The morphology and crystal structure can be well controlled by adjusting the hydrothermal reaction parameters and the molar ratio of Citrate/
Ln
. The size of NaYF
4
∶ Eu
3+
nanoparticles is about 50 nm
and the size of NaYF
4
∶ Eu
3+
hexagonal prism is about 1 000 nm1 500 nm (side lengththickness). The possible formation mechanism of NaYF
4
∶ Eu
3+
nanoparticles/hexagonal prism are proposed based on the experimental results. It was found that the morphology of samples is determined by the intrinsic crystal structure and the selective adsorption of citrate. The FT-IR spectra prove the presence of the citrate ligands at the surface of the nanoparticles/hexagonal prism. Therefore
the NaYF
4
∶ Eu
3+
nanoparticles can be dispersed in the water. The NaYF
4
∶ Eu
3+
samples exhibit strong orange (588 nm) and red (614 nm) emissions under 395 nm excitation
which are assigned to the
5
D
0
7
F
2
and
5
D
0
7
F
1
transition
respectively. From the intensity ratio of
5
D
0
7
F
2
and
5
D
0
7
F
1
transitions
it can be concluded that more Eu
3+
ions are occupied the sites of inversion centers in the cubic-phase NaYF
4
∶ Eu
3+
nanoparticles.
关键词
Keywords
references
Milliron D J, Hughes S M, Cui Y, et al. Colloidal nanocrystal heterostructures with linear and branched topology
. Nature, 2004, 430 (6996):190-195.
Zhao J, Sun Y, Kong X, et al. Controlled synthesis, formation mechanism, and great enhancement of red upconversion luminescence of NaYF4 ∶ Yb3+, Er3+ nanocrystals/submicroplates at low doping level
. J. Phys. Chem. B, 2008, 112 (49):15666-15672.
Li Yue, Zhai Haiqing, Yang Kuisheng, et al. The upconversion luminescence properties of nanocrystal NaYF4 ∶ Er3+ ,Tm3+ , Yb3+ synthesized by hydrothermal method
. Chin. J. Lumin.(发光学报), 2009, 30 (2):239-242 (in Chinese).
Sun Jiayue, Yang Zhiping, Du Haiyan. Upconversion luminescence properties of NaYF4 ∶ Tm3+, Yb3+ synthesized by co-precipitation method
. Chin. J. Lumin. (发光学报), 2009, 30 (2):195-200 (in Chinese).
Tian Z R, Voigt J A, Liu J, et al. Complex and oriented ZnO nanostructures
. Nat. Mater., 2003, 2 (12):821-826.
Lin-Vien D, Norman B Colthup, William G Fateley, et al. The Handbook of IR and Raman Characteristic Frequencies of Organic Molecules
. New York: Academic Press, 1991, 137.
Wang Y, Wong J F, Teng X W, et al. Pulling nanoparticles into water:phase transfer of oleic acid stabilized monodisperse nanoparticles into aqueous solutions of -cyclodextrin
. Nano Lett., 2003, 3 (11):1555-1559.
Li Yanhong, Hong Guangyan. Synthesis and spectra properties of nanocrystalline GdPO4 ∶ Eu3+
. Chin. J. Lumin.(发光学报), 2005, 26 (5):587-591 (in Chinese).